With the growing use of remote access computer networks which provide a large number of subscribers, access to "data banks" for receiving, storing, processing and otherwise furnishing information of a confidential, financial, or otherwise proprietary nature, the question of security has come to be of increasing concern. Generally, present day computing and/or banking centers have or need elaborate procedures for maintaining physical security at locations where the central processor, data storage, or cash issuing facilities are located. Examples of this type of security are guards, special keys, special password codes that must be entered into a terminal device at the door of the computing or banking central location, etc. Such security procedures, while providing a measure of safety in keeping out unauthorized individuals with respect to physical areas of the facility, are not really effective for remote terminal applications where unauthorized people may, for example, obtain someone else's password, code number, etc., which will then allow them unauthorized access to central system records which could further allow access to unauthorized data, unauthorized issuance of money at a cash issuing terminal, etc.
In relatively recent years, some rather sophisticated cryptographic security systems have been devised and built into banking and other highly secure systems where unauthorized access is undesirable. However, even with these sophisticated systems, if a person somehow penetrates the main system and obtains a secret "key", posing as another authorized user is usually a trivial matter.
It has long been thought possible to devise means for having a remote subscriber or user utilize his own signature as a key to gain entry into the system as with a "voice print", "fingerprint", etc. However, no system has ever been implemented which provides the required degree of security in such handwriting or signature recognition systems without an unacceptable rejection of authorized or valid signatures. Some prior art techniques rely essentially on character recognition and pattern super-position types of analysis methods based on x-y positional data. However, such systems do not work well due to the inherent variability of such positional information.
What is desired is a system which can successfully provide rejection of forged signatures and yet allow a very high percentage of authorized signatures to pass through the system without false rejection. This latter factor is a problem because many signatures vary considerably from time to time depending upon such factors as fatigue, general mental and physical state, writing position, etc. It is, of course, a prime requisite, for such a system to be successful in a commercial environment that it be able to allow for reasonable variations in an individual's signature and still be able to discriminate against forgeries.